Fuse for missile



Sept. 25, 1956 T. J. MCCUISTION FUSE FOR MISSILE Filed June 9, 9

INVENTOR. 7&MMi f/VCC'0/5T/0N BY flrroelvsys United This invention relates to the art of fuses and is primarily intended for use in rocket missiles of the nonrotating type.

More specifically, my present invention is for an improved device for arming a contact-detonated fuse of a rocket non-rotating missile.

As may be understood by those who are familiar with the art to which this invention relates, prior devices for this same general purpose have been operated either mechanically with springs that may be wound in a manner similar to a Watch or clock mechanism, or electrical- 1y; but such devices are quite complicated and are open also to other objections from the standpoints of efficiency and dependability.

The general purpose of my present invention is to devise a hydraulic arming means which is characterized by marked simplicity of structure and etficiency and dependability of operation.

A more specific'object is to provide such a device in which the arming is effected by the accelerating movement of the rocket with which. employed and in which the timing of the arming operation may be determined by due regard to the rocket acceleration as well as the variable elements within the device.

Another object is to provide such a device that might be made compensating for outside temperature.

Anotherobject is to provide such a device with means whereby the arming may be effected at a predetermined distance from the point where the missile is launched.

Another object is to provide such an arming device to which there may be added a conventional base type of detonator without interfering with its operation.

Another object is to provide such an improved device that will, at the same time, meet the exacting military requirements.

A more specific object is to provide against premature arming that might be caused by accidential dropping, collision of the launcher, or in any way other than through the forces set up within the discharged rockets and missiles, so as to thereby increase the degree of safety with which such a device may be handled;

Other objects will appear from the following description and claims when considered together with the accompanying drawing.

Fig. 1 is a longitudinal sectional view of my present improved device, corresponding to line 1--1 of- Fig.

Fig. 2 is a partial longitudinal sectional view taken in the same plane as Fig. 1 but showing the partsin armed position whereas they are shown in unarmed position in Fig. l;

. Fig. 3 is a cross sectional view taken on line 33 of Fig. 1;

Fig. 4 is a view corresponding generally to line 4-4 of Fig. 5 and showing some parts in elevation and other parts in section; I

Fig. 5 is a transverse sectional view taken on line 5-5 of Fig. 1.

Referring to the drawing in detail, cone 1' of suitable rates Patent metal is secured at its rear end upon the correspondingly formed forward part of metal body 2 which is screwthreaded at 3 for attachment to rocket missile M and has screw threads 4 for connection of a booster (not shown). Secured within the forward end of cone 1 is nose portion in. Metal body 2 has inwardly extending transverse wall portion 5 through which extends guide member 6 with retaining nut 7 upon the rear end thereof and in engagement with the wall 5, there being provided the sealing ring 8 of suitable elastic composition. The detonator 9 is housed within the rear end of the suitably formed portion of the enlarged part of the guide member 6 and is held in place by the inwardly extending flange 7a of the nut 7.

The enlarged part of the guide member 6 has a cavity 10 of transversely extending cylindrical-like form to accommodate the safety bar 11 whose end portions are of cylindrical form for rotatable engagement within the cavity 10, while the middle part of this safety bar 11 is cut away so as to provide a reduced full portion 11b with the squared surfaces and 11d, respectively. The safety bar 11 is adapted to be rotated about a transverse axis so as to occupy either of the two positions indicated in Figs. 1 and 2, respectively. When in the po sition indicated in Fig. 1, the fullportion 1115 will extend across the path of the firing pin 12 which is capable of longitudinal movement within the guide member 6; and, in this position, the tapered rear end of the firing pin 12 will rest against the squared surface 11c of the full portion 11b of the safety bar 11, thereby withholding the firing pin 12 from entering the registering opening (in of the guide member 6 and opening 9a of the shell of the detonator 9, as illustrated in Fig. l of the present drawing. Thus, with the parts in such position (Fig. 1), the firing pin 12 is prevented from engaging the detonator 9. The other squared surface 11d of the safety bar 11, that is normal to the surface 110, is adapted for engagement with the squared end of the transversely extending lock pin 13 so as to hold the safety bar 11 in the position indicated in Fig. 1 of the present drawing.

The safety bar 11 has connected to one end thereof, one end of coil spring 14 whose other end is anchored at 14a in the guide member 6; and the tendency of this spring is to turn the bar 11 about a transverse axis towards the position indicated in Fig. 2 hereof. The other end of the safety bar 11 is provided with a slot 15 adapted to receive a screw-driver or other suitable tool for turning the same to the position indicated inFig. l of the drawing, that is against the spring 14.- An annular washer 15a may he provided about the slotted end of the safety bar 11; and the adjacent annular portion of the guide member 6 about the end of the opening 10 may be peened over the washer 15a so as to hold the safety bar 11 in assembly.

As a means for holding the safety bar 11 in such set position (Fig. l), the transversely reciprocatablelock pin 13 has a squared inner end that is adapted to engage the squared surface 11d of the safety bar 11. The lock pin 13 is adapted for such straight-line movement within an opening provided in the wall of the guide member 6, as will be understood from Figs. 1, 2- and 5 of the. present drawing; The lock pin 13 maybe held in locking. position by the annular ring 16 which is in turn held forwardly in such position by the coil spring 17 forcing the ring 16 against the shoulder 18 on the guide member 6, the spring 17 having bearing engagement at its rear end against the seat provided in the transverse wall portion 5 of the guide member 6, as indicated in Fig. l of the present drawing.

As a means for disengaging the ring 16 from. engagement with the lock pin 13, there is provided the plunger 19 that is positioned 'coraxially about the guide member 6 and is adapted for therealong so as to contact the ring 16 and disengage the same from the pin 13. The coil spring 20 surrounds the guide member 6 and has bearing engagement at its one end against the annular shoulder 20a provided on the guide member 6 and, at its other end, against the shoulder 20b within the plunger 19. The normal tendency of spring 20 is to force the plunger 19 forwardly; and the forward end of the plunger 19 may be beveled so as to better accommodate the same within the tapered forward part of the cone 1. The forward end of the plunger 19 may be provided with a port 21 having an annular edge-form of valve seat for engagement by the needle valve 22 which has screw-threaded engagement within the port 21. By means of a screw driver or other suitable tool engaging the slot in the end of the valve 22, it may be adjusted so as to vary the size of the opening and hence the amount of the flow therethrough.

The space within the combined casing provided by the members 1, 1a and 2, is intended to be filled with a suitable hydraulic fluid; and sealing rings or other suitable sealing means of elastic composition may be provided at the points 23, 24 and 25, as indicated in the present drawing.

The forward end of the firing pin 12 has an enlarged portion 12a that fits snugly within the cavity in the end of the nose portion 1a of the casing, there being a dish shaped frangible retainer 26 surrounding the firing pin between its enlarged portion 12a and the bottom of the cavity; and the closure disk 27 is seated upon an annular shoulder and is held in place by peening the edge of the same over the annular edge of the nose portion 1a about the cavity just referred to. The nose portion 1a of the casing has screw-threaded engagement with the forward end of the guide member 6. I

As will be observed, the tightening of the nut 7 at one end of the guide member 6 and the screw-threaded engagement between the other end of the guide member 6 and the nose member 1a may be depended upon to hold the parts 1, 1a and 2 together, the rear end of the cone 1 having tapered wedge engagement with the body part 2, and the forward end of the cone 1 having bearing engagement against the annular shoulder provided upon the nose member 1a.

As will be seen from the accompanying drawing, the sealing ring 23 is located at the joint between the nose member 1a and the cone member 1; the sealing ring 24 is located at the joint between the nose portion 1 and the guide member 6; and the sealing ring 25 is located at the joint between the cone portion 1 and the body 2.

The plunger 19 is adapted to enter a cavity in the body member 2, with suitable clearance therebetween, as indicated in Fig. l of the present drawing; and the space within the body member 1 is of sufficient extent to accommodate the rearward movement of the plunger 19 towards its engagement with the ring 16. In fact, the plunger 19 may be within the cavity of the body member 2 at all times, as will be seen from Fig. 1 of the drawing.

Upon launching the rocket missile, the parts of my present device will have been set in the position indicated in Fig. 1 of the drawing and the interior of the casing will have been filled with a hydraulic fluid of suitable density and viscosity. It is assumed also that the springs have been selected with respect to weight and load for the required resistance to the movement of the plunger 19. Also, there should be proper clearances between the plunger 19, body member 2 and guide member 6, and of course between the firing pin 12 and the guide member 6; and the weight of the plunger 19 should also be taken into account. Due regard will be given to the weight and other essential characteristics in selecting the metals for the several constituent parts of the present device so as to make possible the manner of operation herein contemplated.

In order to provide for arming of the fuse within a longitudinal movement rcarwardly moderate range, the clearances provided by standard machine tools are sufiicient to control the flow area of the hydraulic fluid; but, in case closer arming limits should be desired, the metering screw 22 may be resorted to so as to vary the rate of flow of this fluid to an even finer point.

In the present form of device, the fuse is intended to be point-detonating; and it is to be understood that provision may be made in my present device for operation in either a super-quick manner or with delayed action by means of standard boosters not here shown.

In actual operation, the arming of this fuse will take place when the plunger 19 shall have been moved by the action of the rocket acceleration through the hydraulic fluid to the point where it engages and moves the ring 16, against the tension of the spring 17, out of the plane of the lock pin 13 which is then automatically forced radially outwardly under the influence of the spring 14. At the same time, the spring 14 turns the safety bar 11 about its axis so as to move the squared surface of its full portion out of the path of the firing pin 12. That is to say, the parts will be moved from their position of Fig. 1 to that of Fig. 2 so that the firing pin 12 will then have access to the detonator 9; and the fuse is thus armed and is ready for firing upon impact of the nose or forward end of the same so as to cause the firing pin 12 to enter the detonator 9 which fires the booster charge not here shown. The arming of the fuse will take place at a predetermined distance of the same from the point of the launching of the missile in accordance with the resistance to the movement of the plunger 19, which may be governed by due consideration to the several factors above mentioned.

To recapitulate, the movement of the plunger 19 in my present device may be determined by the force of the rocket acceleration, the selection of the metals for the several parts and with due regard to the weight of the plunger 19, the clearances between the several parts as above pointed out, the weight and load of the springs, and the density and viscosity of the hydraulic fluid.

Also, the eflects of temperature change may be compensated for by the use of a body material that has a lower coefficient of thermal expansion than the material of the plunger, the outer clearance being more readily affected by the temperature changes than the inner clearance. Also, it is possible to select a hydraulic fluid which has a viscosity-temperature slope approximating the change in volume slope of two dissimilar materials due to temperature.

Notable among the practical advantages that are obtained with the present invention are those of comparative simplicity of structure and dependability of operation.

It should be pointed out that this device also meets the several rigid requirements of the Government military establishment, as will be now briefly noted. (1) This fuse will fit existing projectiles in the manner required. (2) This fuse is capable of withstanding long storage conditions at high and low temperatures and is capable of operating under such conditions. (3) This fuse does not alter the ballistic characteristic of the projectile. (4) This fuse also meets the standard requirements with respect to the time of actuation, performance and safety. And it might be added that this fuse possesses the necessary rigidity against the vibrations due to speed of flight of the missile of the type herein contemplated.

Also, it is possible to add to the present device a conventional base type of detonator so that a firing pin can rupture the cap by striking the reverse or rear side of the same, as well as the forward side of the cap as herein disclosed.

Another important advantage of my present device resides in the safety with which a shell or rocket can be transported, handled or dropped without creating a the arming of the present device safety hazard, since depends upon the terrific inertia through a time interval incident to the firing of the shell.

Other practical advantages will no doubt suggest themselves to those who are familiar with the particular art to which the present invention relates. 7

It is to be understood that the present disclosure is merely for the purpose of illustration and that there might be devised various modifications thereof without departing from the spirit of my invention as herein set forth and claimed.

What I claim is:

1. A fuse for a missile of the non-rotating type, comprising a body open at its forward and rear ends and provided with means for attaching the open rear end thereof in operative relation to the missile, a hollow openend guide means extending co-axially Within and along said body, a detonator within the rear open end portion of said guide means, a firing pin extending co-axially within said guide means and having its rear end in registry with said detonator and with its forward end exposed for impact, a spring-actuated holding means normally tending towards inactive position so as to release said firing pin, means for restraining said springactuated holding means so as to prevent release of said firing pin, said body having a chamber adapted to contain a hydraulic fluid about said guide means, and a plunger surrounding said guide means and movable along the longitudinal axis of said body of the missile against the resistance of the movement of the hydraulic fluid for releasing said restraining means so as to thereby permit access of said firing pin to said detonator, said plunger having a passage therethrough from the forward to the rearward ends thereof, and adjustable means for varying the flow of the hydraulic fluid through said passage so as to thereby vary the rate of travel of said plunger through the hydraulic fluid.

2. A fuse for a missile of the non-rotating type, comprising a hollow open-end body having a centrally apertured transverse wall across the rear part thereof so as to provide forward and rearward chambers within said body, the rear end of said body having means for attaching the open end thereof in operative relation to the missile, a hollow open-end guide means extending coaxially Within and along said body and having its rear end portion extending through said central opening in said transverse wall of said body, means for securing said guide means in sealed condition within said wall, of said body in sealed means for closing the forward end by force of acceleration condition about the forward end portion of said guide means, a detonator within the rear open end of said guide means, a firing pin extending co-axially within said guide means and having its rear end in adjacent registry with said detonator and with its forward end extending through said guide means so as to be exposed for impact, a spring-actuated holding means normally tending radially outward towards inactive position so as to release said firing pin, an annular member surrounding said guide means and adapted to occupy position in the plane of said holding means for restraining the same against being forced radially outwards, spring means for holding said annular member in such restraining position, said hollow body being adapted to contain a hydraulic fluid therewithin and about said guide means, and a plunger surrounding said guide means and movable along the longitudinal axis of said body by force of acceleration of the missile against the resistance of the movement of the hydraulic fluid, said annular member extending radial- 1y outwardly into the path of 'said plunger so as to be released from restraining position and to thereby permit access of said firing pin to said detonator, said spring means for said annular member being in the form of a coil spring surrounding said guide means with bearing engagement at its ends with said annular member and with said transverse wall of said body, said guide means being provided with a shoulder, a coil spring surrounding said guide means and having abutment at its rear end against said shoulder and at its other end against the rear end of said plunger, said plunger having a passage therethrough from the forward end to the rearward end thereof, and adjustable means for varying the flow of the hydraulic fluid therethrough so as to thereby vary the rate of travel of said plunger through the hydraulic fluid.

References Cited in the file of this patent UNITED STATES PATENTS 527,250 Smith Oct. 9, 1894 1,142,375 Smith June 8, 1915 1,375,466 Ragsdale Apr. 29, 1921 1,393,585 Sutton Oct. 11, 1921 FOREIGN PATENTS 22,651 Great Britain 1900 5,301 Great Britain 1913 129,041 Great Britain July 10, 1919 

